Pedigree Traits

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Pedigree Traits
2015-04-06 20:30:26
BIO 183,Genetics
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  1. Characteristics of a Dominant Pedigree
    • Every affected individual has at least one affected parent
    • If an affected individual mates with an unaffected individual, and the mating results in a 50% chance of transmitting the trait to each child, the the affected individual is heterozygous
    • Two affected individuals may have unaffected children (meaning that they are heterozygous)
    • Traits usually do not skip a generation
  2. Characteristics of a recessive pedigree
    • An individual who is affected may have unaffected parents
    • All the children of two affected individuals are affected
    • In pedigrees involving rare traits the unaffected of an affected individual may be related to each other
    • If a normal individual mates with an individual who is affected, all children produced are normal; unless at least one child is affected, meaning that the normal parent is heterozygous; then at least half the children should be affected
  3. Characteristics of Sex-Linked Dominant Pedigree
    • Affected males must come from affected mothers
    • Approximately half of the children of an affected mother are affected
    • Affected females come from affected mothers or fathers
    • All females, but no sons, of an affected father are affected
  4. Characteristics of a Sex-Linked Recessive Pedigree
    • Most affected individuals are male
    • Affected males result from mothers who are known to be carriers (heterozygous); approximately 50% of sons will be affected
    • Affected females come from affected fathers and carrier mothers
    • Affected mothers must have affected sons